Ultraviolet curable organopolysiloxane composition, silicone gel cured product and method for producing same, and pressure sensor

Abstract

An ultraviolet curable organopolysiloxane composition which contains:(A) a linear or branched organopolysiloxane which contains, as monovalent substituents bonded to a silicon atom at an end of the molecular chain, at least three groups represented by formula (1) and / or formula (2) in each molecule, while having the main chain composed of repeated diorganosiloxane units(in the formulae, a represents a number of 1-3; and the broken line represents a bonding hand);(B) a linear or branched organopolysiloxane which contains at least two groups represented by formula (3) in each molecule, while having the main chain composed of repeated diorganosiloxane unitsR1bR23-bSi  (3)(in the formula, R1 represents an alkenyl group; R2 represents a monovalent hydrocarbon group; and b represents a number of 1-3); and(C) a photoinitiator.With use of this ultraviolet curable organopolysiloxane composition, the hardness of a cured product obtained therefrom is easily controlled, and good surface curability and good curability in deep portions are achieved even in the presence of oxygen. Consequently, this ultraviolet curable organopolysiloxane composition enables the achievement of a silicone gel (a gel-like cured product) which has been cured at a substantially uniform crosslinking density (with a substantially uniform penetration) without depending on the irradiance of ultraviolet light (the amount of irradiation energy).

Description

TECHNICAL FIELD[0001]This invention relates to an ultraviolet-curable organopolysiloxane composition which is effectively curable with a wide range of UV illuminance and good in surface cure and depth cure and facilitates to adjust the hardness of a cured product, and more particularly, to a UV-curable organopolysiloxane composition which upon UV irradiation, is improved in reducing oxygen inhibition and consistently cures even in the presence of oxygen into a silicone gel (gel-like cured product) having a substantially constant crosslinking density (substantially constant penetration), independently of the UV dose (irradiation energy amount); a silicone gel cured product obtained by curing the composition, a method for producing the cured product, and a pressure sensor comprising the cured product.BACKGROUND ART[0002]The efforts to enable simplification and cost reduction of manufacturing processes, collaborated with the trend toward energy saving from environmental considerations,...

AI Technical Summary

Benefits of technology

The UV-curable organopolysiloxane composition described in this patent allows for easy adjustment of hardness, can be cured with a variety of UV levels, and is resistant to oxygen inhibition. Compared to previous UV-curable silicone compositions, it is also easier to work with.

Problems solved by technology

In particular, most of the processes for manufacturing optical, electric and electronic devices and displays involve the step of heating at high temperature for curing of bonding, encapsulating and embedding materials, the heating step requiring enormous energy, time and equipment.

When this composition is applied to electric / electronic substrates, for example, there is concern that the substrates can be corroded.

These methods, however, are difficult to adjust the cured products to the desired hardness or penetration, and the hardness or penetration largely depends on the dose of UV irradiation.

In addition, radicals have an extremely short life and can be readily deactivated with oxygen or the like.

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